I'm interested to see if you can help me identify a horror/sci-fi movie I saw years ago. The movie itself was probably the 1980s and I remember seeing it on HBO. I only caught the movie from what I thought was its last scene. The scene involved men, possibly some sort of military, rappelling up out of a cave or crater (is that even possible?) while firing automatic weapons. They appeared to be trying to escape a large wooden crate that was sitting on the floor of the room that was in the cave/crater. Tentacle-like arms burst forth from the crate and shot out at these rappelling military guys. That's when it was revealed that there was some sort of fleshy blob inside the crate and it shot these tentacle things like spears impaling the rappelling people so they fell to their deaths. That's all that I remember.

I've done extensive internet searches that bore no fruit. So far my only guess is that it could be the film Contamination or its sequel, Alien 2: On Earth/Alien Terror/Strangers. However, I have seen neither films.